The invention is concerned with paper towel dispensers, particularly dispensers adapted to accommodate a primary roll in a first station and a secondary roll in a second station, with provision for transfer mechanism automatically operative to feed toweling sequentially from the primary roll and then from the secondary roll upon exhaustion of the primary roll.
Although the invention is particularly concerned with certain features of construction for mounting the rolls and for effecting the transfer in a paper toweling dispenser, it is to be understood that various of the features are applicable to dispensers for other continuous webs, for instance, toilet tissues or any other web supplies involving primary and secondary sources from which it is desired to effect the feed sequentially, first from the primary supply and then from the secondary supply. Since the invention is of special utility in the field of paper towel dispensers, such as those commonly installed in toilet rooms, the invention is herein illustrated and described as applied to an embodiment of a paper towel dispenser.
As is known, transfer dispensers commonly are enclosed in a cabinet and incorporate two roll accommodating stations, one of which is herein identified as the primary roll station, and the other as the secondary roll station. The general purpose of this configuration is to facilitate janitorial maintenance while at the same time assuring constant availability of toweling supply. In a typical embodiment, the roll in the primary station has only a minor fraction of the total toweling initially included in that roll, and the web from the primary roll is threaded through the feed mechanism and is discharged or delivered from the dispenser, frequently by the turning of a handcrank or actuation of a lever. The second station, provided for the secondary roll, accommodates a fresh or full roll which remains as a reserve supply in the dispenser until the web from the primary roll is exhausted.
When the attendant or service personnel inserts a new roll in the secondary station, the roll which had previously occupied that position is first shifted to the primary station, the web of this roll remaining in engagement with the feed mechanism; and then the web of the secondary roll is brought into a position near the feed mechanism, but not in engagement therewith. In transfer dispensers, provision is made for introducing the web of the secondary roll into the feed mechanism either toward the end of the feed of the web from the primary roll or after complete exhaustion of the primary roll web.
Several different forms of dispensers of the general type referred to above are known, but certain types of problems arise with various of the prior known dispensers. For example, in some cases, the transfer of feed from the primary roll to the secondary roll has a tendency to occur prior to complete exhaustion of the paper web from the primary roll, with consequent concurrent delivery of both webs during the feed of the final portion of the primary roll web. This represents a waste of paper, and the arrangement of the present invention is adapted to assure that the feed of the web from the secondary roll does not occur until complete or at least substantially complete exhaustion of the web from the primary roll.
In some of the prior dispensers, the transfer operation is unreliable at least from time to time; and in consequence, in some cases, the primary roll web is exhausted and the secondary roll web is not delivered at the time of exhaustion of the primary web. Another objective of the present invention is to greatly increase the reliability of the transfer function.
In some instances in prior arrangements, the transfer mechanism has been arranged to engage the web in only a single relatively limited region transversely of the secondary roll web between the side edges thereof; and in some cases where the leading end of the secondary roll web has been torn off or folded under in the region where the transfer mechanism would normally operate, the transfer would be unreliable or might fail. It is an object of the present invention to overcome problems of this type, particularly by providing more than one transfer device respectively engageable with the web of the secondary roll in spaced retions thereof, preferably adjacent to each side edge thereof. In this way, if one edge or corner piece of the web from the secondary roll is torn off or folded under, the transfer will be effected by the transfer mechanism associated with the outer edge of the web.
Still further, in some prior arrangements, there is a tendency under certain conditions for the transfer mechanism to be prematurely triggered. Sometimes, this can happen as a result of an impatient towel user delivering a manual blow to the cabinet, and thereby jarring internal parts to such an extent as to prematurely trigger the transfer. It is also an objective of the present invention to positively assure against premature triggering of the transfer mechanism at least until a point representing substantial exhaustion of the primary web.
It is another object of the invention to provide an arrangement which limits the size of the secondary or reserve roll which may be transferred to the primary roll station at the time the dispenser is serviced.
Still another object of the present invention is to provide a roll-mounting structure, especially adapted for use in the station for the primary roll, such structure being arranged to provide for alternative support of rolls of paper webs of different width.